Solar architecture

Solar architecture is an architecture approach that takes into account the Sun to harness clean and renewable solar power . It is related to the fields of optics , thermics , electronics and materials science . Both active and passive solar housing skills are involved in solar architecture.

Initial development of solar architecture has been limited by the rigidity and weight of standard solar power panels. The continued development of photovoltaic (PV) solar thin film has provided a lightweight yet robust vehicle to harness solar energy to reduce impact on the environment.

History

The idea of passive solar building design first appeared in Greece around the fifth century BC. Up until that time, the Greek’s main source of fuel was charcoal , but due to a major shortage of wood to burn they were forced to find a new way of heating their dwellings. [1] With their motivation, the Greeks revolutionized the design of their cities. They began using the building materials that were absorbed by solar energy, and then started the building. These revolutions, coupled with an overhang that kept the hot summer sun, created structures that required very little heating and cooling. Socrateswrote, “In houses that look towards the south, the sun penetrates the portico in winter, while in summer the path of the sun is right over our heads. [2] From this point on, most civilizations have their structures to provide shade in the summer and heating in the winter. The Romans on the side of the sea. [1] Another simpler example of early solar architecture is the cave dwellings in the South-Western regions of North America. Much like the Greek and Roman buildings, the cliffs in which the indigenous peopleof this region built their homes were oriented towards the south with an overhang to shade the sun as much as possible. [3]

Active solar architecture involves the moving of heat and / or coolness between a temporary heat storage medium and a building, typically in response to a thermostat’s call for heat or coolness within the building. While this principle sounds useful in theory, significant engineering problems have almost all active solar architecture in practice. The most common form of active solar architecture, rock bed storage, air conditioning, and the like, usually grew in the rock, which was blown into houses, along with dust and radon in some cases.

A more complex and modern incarnation of solar architecture was introduced in 1954 with the invention of the photovoltaic cell by Bell Labs . Early cells were extremely inefficient and therefore not widely used, but throughout the years government and private research has improved the efficiency to a point where it is now a viable source of energy. Universities were some of the first buildings to embrace the idea of ​​solar energy. In 1973, the University of Delawarebuilt Solar One, which was one of the world’s first solar powered houses. As photovoltaic technologies keep advancing, solar architecture becomes easier to accomplish. In 1998 Subhendu Guha developed a photovoltaic shingles and recently a company called Oxford Photovoltaics. [4]Although the windows are not scaled up, the company believes that the outlook is very promising. In the company’s mission statement they state, “Moreover, through the deployment of solar cells in areas where solar energy has been built, for example the glass facades of high-rise commercial or residential buildings. “higher proportion of electricity than is possible today, and helping to position PV as a significant factor in the global energy market.” [5]

Elements

Greenhouse

A greenhouse keeps heat from the Sun. In a double glazed greenhouse, three effects occur: no convection (air blocking), ray keeping (the ground absorbs a photon, emits it with lower infrared energy, and the glass reflects this infrared to the ground) and little conduction (double glazing) . It seems that the convection effect is the most important as greenhouses in poor countries are made of plastic.

The greenhouse can be used to grow plants in the winter, to grow tropical plants, as a terrarium for reptiles or insects, or simply for air comfort. It must be ventilated, but not too much, otherwise the convection will make the inside colder, losing the desired effect. The greenhouse may be combined with heat storage or an opaque mask.

Photothermic module

Photothermic modules convert solar light into heat. They easily heat domestic water to 80 ° C (353 K). They are facing the sunny cardinal point, rather pointing towards the horizon to avoid the overheat in summer, and take more calories in the winter. In a 45 ° North place, the module should face the South and the angle to the horizontal should be about 70 °.

The use of intermediate solar heat systems like evacuated tubes, compound parabolic, parabolic trough, is discussed as they correspond to specific, intermediate needs. A customer who wants a photothermic, giving 80 ° C (353 K) hot water with 70-85% efficiency. A customer who wants high temperatures will naturally prefer the solar parabola, giving 200 ° C (573 K) with 70-85% efficiency.

Do it yourself photothermic modules are cheaper and can use a spiral pipe, with hot water coming from the center of the module. Other geometries exist, like gold serpentine quadrangular.

If we have a flat roof, a mirror in front of the photothermic module to give it more sunlight.

The photothermic module has become popular in Mediterranean countries, with Greece and Spain counting with 30-40% of homes equipped with this system, and becoming part of the landscape.

Photovoltaic module

Photovoltaic modules convert solar light into electricity. Classical silicon solar modules have up to 25% efficiency but they are rigid and can not be placed on curves. Thin film solar modules are flexible, but they have lower efficiency and lifetime.

Photovoltaic tiles combines the usefulness of the bathroom by providing tile-like photovoltaic surfaces.

A pragmatic rule is the photovoltaic surface facing the sunny cardinal point, with a latitude-equal angle to the horizontal. For example, if the house is 33 ° South, we will have the photovoltaic surface facing the North with 33 ° to the horizontal. From this rule comes a general standard of roof angle, which is the norm in solar architecture.

Thermal storage

The simplest solar heat water system is to place a hot water tank towards the Sun and paint it in black.

A thick ground of rock in a greenhouse allows to keep some of the heat through the night. The rock will absorb heat in the day and emit it in the night. Water has the best thermal capacityfor a common material and remains a sure value.

Electrical storage

In autonomous (off-grid) photovoltaic systems, batteries are used to store the excess of electricity, and deliver it when needed in the night.

Grid-connected systems can use interseasonal storage thanks to pumped-storage hydroelectricity . An innovative storage method, or compressed air energy storage , is also being studied, and may be applied to the scale of a home or to a room,

White wall

In the Greek islands, the houses are painted in white to heat the heat of the house, making the house cooler. The white walls covered with lime and the blue roofs make the Greek islands by the people for the inside.

Black wall

In Nordic countries, this is the opposite: the houses are painted in black to better absorb the irradiation heat. Basalt is an interesting material as it is naturally black and exhibits high thermal storage capacity.

Solar tracker

Part of, or the whole house can track the Sun’s race in the sky to catch its light. The Heliotrope , the first positive energy in the world, rotates around itself to the sunlight, converted into electricity by photovoltaic modules, heating the house through the translucent glass.

Tracking requires electronics and automatics. There are two ways to the system where Sun is: instrumental and theoretical. The instrumental method uses captors of light to detect the Sun’s place. The astronomical method uses astronomical formulas to know the Sun’s place. One or two axis motors will make the solar system rotate to face the Sun and catch more of its Sunlight.

A photovoltaic gold photothermic module can gain more than 50% of production thanks to a tracker system [6] .

Solar mask

Sometimes the heat becomes too high, so we want a mask to get shadow. The Heliodome has been built in such a way that the roof hides the Sun in the summer to avoid overheating, and lets the sunlight pass in the winter [7] .

As a mask, any opaque material is fine. A curtain, a cliff, a wall, can be solar masks. If a leafy tree is in front of a greenhouse, it can hide the greenhouse in the summer, and let the sunlight go in, in the winter, when the leaves have fallen.

We need to remember that the shadows will not work the same according to the season. The season change to get in the summer, light in the winter, is a general rule for a solar mask.

Solar chimney

A solar chimney is a chimney of outside black color. They were used in Roman antiquity as a ventilation system at a time when electricity did not exist. The black surface makes the chimney heat with sunlight. The air inside gets warmer and moves up, which is at 15 ° C (288 K) all the year. This traditional air-ground exchanger was used to make the house cool in the summer, mild in the winter.

The solar chimney May be coupled with a badgir gold wood chimney for stronger effect.

Solar parabola

A solar parabola is a parabolic mirror that concentrates the sunlight to reach high temperatures. In Auroville’s collective kitchen, a large solar parabola provides heat for cooking.

The solar parabola can also be used for industrial building. The Odeillo solar furnace , one of the largest solar parabola in the world, concentrates the sunlight 10,000 times and temperatures above 3,200 K. No material resists, even diamond melts. It opens the vision of a futuristic metallurgy, using a clean and renewable source of energy.

Examples

One of the first large commercial buildings is an example of 4 Times Square architecture (also known as Condé Nast Building ) in New York City . It has built-in solar panels on the 37th through the 43rd floors and incorporated more energy efficient technology than any other sky scraper at the time of its construction. [4] The National Stadium in Kaohsiung, Taiwan , designed by the world-famous Japanese architect Toyo Ito , is a dragon-shaped structure that has 8,844 solar panels on its roof. [ quote needed ]It was built in 2009 to house the 2009 world games. Constructed completely of recycled materials, it is the largest solar-powered stadium in the world and the surrounding area when it is not in use. Another example of solar architecture is the Sundial Building in China. It was built to symbolize the need for fossil fuels with renewable energy sources. The building is shaped like a fan and is covered in 4,600 square meters (50,000 sq ft) of solar panels. It was named the world’s largest solar powered office building in 2009.

Although it is not yet completed, the Solar City Tower in Rio de Janeiro is another example of what solar architecture might look like in the future. It is a power plant that generates energy for the city during the day. At night, when the sun is not shining, the water will be released to run turbines that will continue to generate electricity. It is set to be revealed at the 2016 Olympic Games in Rio, although the project is still in the proposal phase. [8] A lot of conferences Discuss This Topic As “Green Urbanism” An International Conference Which will be held in Italy From 12-14 October 2016.

Environmental benefits

Using solar power in architecture contributes to a world of clean and renewable energy. This is an investment: the initial price is high, but afterwards, there is almost nothing to pay. On the contrary, fossil and fissile energies are in the beginning. The Fukushima is worth $ 210 billion to Japan [9] , and actually has ruined a country. Global warming has already been a cause of extinction and we can not stop it, insects may eventually replace mammals in life’s reign.

Solar architecture is then anti-crisis. If all houses are to be rebuilt to meet solar architecture standards, this will bring hope, jobs, money, economic growth and a deep feeling of harmony with Nature .

Criticism

According to an article on ECN’s website titled “Architects just want to develop attractive buildings”, an architect’s main purpose is to create a spatial object with lines, shapes, colors and texture. “But they do not have to think about using a solar panel as an interesting building material.” [10] In the article it is stated that solar panels are not an architect’s first choice for building materials because of their cost and aesthetics.

Another criticism of installing solar panels is their upfront cost. According to energyinfomative.org, the average cost for a residential solar system is somewhere between $ 15,000 and $ 40,000 (USD), and about $ 7 per watt. [11] In the article, it says that at today’s rates, it would take 10 years to pay off an average system. A solar panel living more than 20 years [12] , in the end, it becomes a benefit.